The necessity of providing drugs and other solutions to patients in a continuous intravenous fashion is well recognized. In the simplest arrangement, the intravenous injection of drugs or other materials is achieved by establishing the intravenous introduction site into the patient, providing a source of the material or substance, e.g. a drug, to be intravenously introduced into the patient and providing a conduit or tubing between the source and the introduction site through which the material is transmitted to the introduction site.
Oftentimes, it is necessary or at least desirable to introduce a second material into the conduit so that it will flow along with the primary flow of the first material into the patient through the intravenous connection. One method of introducing the second material into the conduit is to provide a multi-branched connector in the conduit in order to allow the second material to be introduced into the conduit through one of the branches of the connection, while the primary flow also passes therethrough.
Any branches of the multi-branched connector used to introduce the second material must be kept closed to maintain sterile conditions and to prohibit the introduction of unnecessary and sometimes harmful fluids through the connector. For this reason, the open branches of the connector usually contain some form of seal. In order to introduce the second material into the conduit the seal in the second branch must be overcome.
One example of a type of seal which may be used is an elastomeric bung positioned over or within the second branch of the connector. In order to introduce the second material into the intravenous feed conduit using this multi-branched connector, a hypodermic needle is inserted through the bung and by means of a syringe connected to the needle, the second material contained in the syringe is injected into the connector and into the intravenous feed conduit.
Another example of a type of seal which is used to prevent introduction of undesired materials into the intravenous conduit when a multi-branch connector is used is to insert into the branch(es) of the connector a one-way valve which requires a specific pressure thereagainst in order to permit any secondary material, whether desired or not, to enter the branch of the connector and ultimately the conduit to the intravenous connection.
These two types of seals have significant drawbacks which need to be overcome. One of the most important drawbacks of using the bung seal in the connector is the necessity of injecting the additional material with a sharp needle. At this time, when the risk of communicable diseases such as hepatitis, AIDS and other viral diseases is great, any use of needles which might result in the puncture of the person administering the material is to be avoided if at all possible. Because the bung is usually very small, the chance of pricking a finger with a needle is substantial. Accordingly, any system for injecting additional material into the intravenous conduit without the necessity of using a needle will be beneficial.
Another drawback is the fact that the presently available systems which incorporate one-way valves require costly materials and construction, since many of these valves are spring- biased. In this regard, it is important that any seal be economical as well as needleless.
There are known several different types of seals or valves which are either one-way or bi-directional and which operate on hydrostatic pressure. Examples of these valves which are patented include: the valve disclosed in Nichols et al., U.S. Pat. No. 4,753,640, which includes a catheter tube of elastomeric material having lumen shapes and slit valves; and the valve taught in Kulle, U.S. Pat. No. 4,346,704, which is a one-way sleeve valve for parenteral solution injection and comprises an outer housing defining an outlet tube and an inner tubular support defining an inlet tube. Furthermore, in the Huang patent, U.S. Pat. No. 4,439,182, a valvular infusion device having valve chambers and resilient one-way valve means which minimize volumetric dead space in disclosed. The device permits one-handed, needleless injection of drugs utilizing commonly known IV apparatus. The patent to Dorman, U.S. Pat. No. 4,657,536, discloses a check valve catheter comprising a central bore and a cross bore or port covered by a thick elastic sleeve to create a check valve. In the Brodner et al. patent, U.S. Pat. No. 4,475,898, a fetal ventriculo-amniotic shunt comprised of a tubular body having a slit-type valve for fluid flow-through is disclosed, and in the Groshong et al. patent, U.S. Pat. No. 4,549,879, a catheter comprising a flexible material with a closed end is taught. A single slit in the Groshong patent catheter wall acts as a pressure actuated valve to permit fluid flow therethrough. Other patents which generally disclose such valves include the Kurtz et al. patent, U.S. Pat. No. 4,752,287, the Atkinson patents, U.S. Pat. Nos. 4,434,810, 4,765,588 and 4,341,239, and the patent to Abramson, U.S. Pat. No. 4,143,853.